How Do You Pronounce Ψ?

Let our journalists help you make sense of the noise: Subscribe to the Mother Jones Daily newsletter and get a recap of news that matters.

Chad Orzel linked yesterday to a post by Sabine Hossenfelder about quantum superposition, and it unsurprisingly degenerated into the usual mush that interpretations of quantum mechanics always do. But then the subject turned to linguistics and it got interesting. As you may know, the quantum wave function is represented by the Greek letter psi (Ψ), with |Ψ²| representing the probability of a particle being found in any particular place.¹ So a reader decided to try on a joke in comments:

How should Psi be pronounced? Is it P-Si, Si, or a superposition of the two? Or is the word not pronounceable until it is spoken, like when Prince changed his name.

But Hossenfelder took the question seriously:

Well, I pronounce it the way that I have heard it most often which in English is “ps-ai” (in German it would be “ps-ee”). The easiest way to find out I guess is to listen to the video? I have no idea which one is the “correct” pronunciation, given that it’s Greek and I don’t speak Greek, but I can tell you that if you pronounce it this way physicists will know what you are talking about.

Huh. I’ve always pronounced it sigh, rhymes with pie. It never occured to me that you’d pronounce the initial P.² So I googled around a bit and got conflicting answers, which I suppose is very on-brand. However, on one particular site the speaker was clearly pronouncing it p-sigh, but with just the barest emphasis on the P. The best I can describe it is that it sounded as if the P was trailing off before it even got started, followed by a normal pronunciation of sigh.

So I guess this is a question for physicists, or anyone who’s taken a quantum physics course. Is Ψ usually pronounced with its initial P? If so, how distinct is it?

¹More or less. Don’t @ me with your eigenvalues and inner products.

²And you don’t pronounce the initial P if you’re using psi as short for psionic. We are talking here solely about the pronunciation of Ψ in its quantum mechanical sense.

UPDATE: Answer here!

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. It's our first time asking for an outpouring of support since screams of FAKE NEWS and so much of what Trump stood for made everything we do so visceral. Like most newsrooms, we face incredibly hard budget realities, and it's unnerving needing to raise big money when traffic is down.

So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate